The present invention relates, generally, to lift attachments, and, more particularly, to load bearing attachments mounted to multipurpose loader buckets for earth moving equipment.
Heavy earth moving equipment typically includes multi-purpose loader buckets or backhoes which are well adept for moving and hauling sand, gravel, landfill or the like. Due to their versatility, speed and loading capacity, these front-end loaders are especially suitable for construction, excavation and agricultural applications. Typically, a tractor or the like is fitted with a pair of hydraulically driven lift arms which raise, lower and pivot the multi-purpose bucket for earth moving use.
While these front-end loaders are quite versatile to perform multiple earth moving functions, these buckets are inadequate for moving bulky or elongated items which are unable to fit therein such as large rocks, beams and pipes. Often, a separate forklift vehicle must be employed to perform these hauling tasks. This of course substantially adds to construction costs, as well as consumes space.
As a result, various implements have been developed which adapt these buckets for forklift use. Such adaptations not only increase the versatility of the front-end loaders, but they eliminate the cost and burden associated with the use of separate forklift vehicles. These implements generally include two or more forklift members fixedly spaced-apart from one another, and removably mounted to a lower support member of the front-end loader bucket. Usually, these forklift members extend under the loader bucket support member for structural mounting thereto, while a clamping assembly is employed to releasably clamp the forklift members to a leading edge portion of the support member. A rear portion of each forklift member is then mounted to an upper rear portion of the loader bucket for stability. Typical of these patented designs are disclosed in U.S. Pat. Nos.: 4,411,585; 4,242,035; 4,125,952 and 3,706,388.
While these forklift implements are adequate for hauling and carrying relatively low to middle weight items (i.e., under 10,000 lbs), the lifting of heavy weight objects may cause severe damage to the implement and/or the loader bucket. Due to the extreme cantilever forces concentrated at contact points along the leading edge of the lip portion, the clamping assembly of the implement and/or the lip portion of the bucket leading edge may be caused to irreparably bend or deform during heavy weight use. Consequently, repair or replacement costs can be substantial.
Other forklift implements have been developed which are primarily supported atop the support member of the loader bucket. However, these designs similarly fail to distribute the cantilever forces across the loader bucket. During heavy load use, the extreme cantilever forces are also concentrated at contact points along the leading edge of the lip portion. Typical of these patented structures are disclosed in U.S. Pat. Nos.: 4,329,103 and 3,667,633.
Thus, a forklift implement for use with a front-end loader is desirable which can accommodate relatively heavy weights without damaging the loader bucket and/or the implement.
To achieve the foregoing, the present invention relates to a load bearing lift attachment apparatus for a multipurpose loader bucket. A first jaw of the loader bucket is movably mounted to a second jaw thereof between an opened condition and a closed condition. The first jaw includes a support member transversely extending from one side to an opposite side of the loader bucket. A front portion of the loader bucket terminates at a transversely extending leading edge, while an opposite rear portion thereof terminates at a rear edge. The second jaw includes an engaging wall transversely extending from the loader bucket one side to the opposite side thereof. The engaging wall further terminates at an engaging edge, and is formed to engage the rear portion of the jaw support member in the closed condition. The lift attachment apparatus of the present invention includes a lift member formed and dimensioned to engage an object to be lifted; and a support device removably coupling the lift member to the loader bucket. The support device is configured to cooperate with the first jaw and the second jaw, in the closed condition, to distribute the cantilever forces, caused by the weight of the object acting on the loader bucket, across a substantial transverse portion of the support member of the first jaw and the engaging wall of the second jaw.
In one configuration, the support device includes a load bearing member formed to extend transversely across an upper surface of the first jaw support member for support thereatop. A rear coupling member of the support device is adapted to simultaneously engage the rear portion of the support member and the engaging wall of the second jaw to distribute a portion of the cantilever forces therebetween, when in the closed condition. The rear coupling member may further include a contacting portion having a forward surface and an opposed rearward surface. Each surface extends transversely across and substantially parallel to a substantial portion of the rear edge of the first jaw support member. The forward surface is formed to be in abutting contact with the rear edge, while the rearward surface is formed to be in abutting contact with the engaging edge of the engaging wall. This enables supportive alignment therebetween, when the load bucket is in the closed condition.
In another embodiment, the rear coupling member further includes a lower lip portion extending rearwardly from the rearward surface of the contacting portion. The rear coupling member is formed and dimensioned such that when the loader bucket is moved to the closed condition, the engaging edge of the second jaw engaging wall substantially seats in an intersection region between the lower lip portion and the rearward surface of the contacting portion of the coupling member. Further still, the rear coupling member includes an upper lip portion extending rearwardly from the rearward surface of the contacting portion. This lip portion is formed and dimensioned to supportively seat against an opposed upwardly facing surface of the engaging wall when the loader bucket is in the closed condition.
In yet another embodiment, the lift member includes an elongated forklift prong mounted to and extending forwardly of a transversely extending wing portion of the support device. A mounting device is adapted to removably mount the lift member at one of a plurality of positions transversely along the wing portion. A stabilizing member of the mounting device extends rearwardly from the wing portion to cooperatively engage the rear coupling member for stabilization thereof.
In another aspect of the present invention, a forklift attachment apparatus is provided for a multipurpose loader bucket having a support member terminating at a transversely extending leading edge and an opposite transversely extending rear edge thereof. The attachment apparatus includes a support device removably coupled to the loader bucket; and a pair of elongated forklift members formed and dimensioned to extend forwardly of the leading edge for selective engagement with an object to be lifted. Each the forklift member is adapted to removably mount to the support device at a respective one of a plurality of positions transversely along the leading edge of the loader bucket for selective space-apart distances therebetween.
In one configuration of this embodiment, the support device includes track assembly extending transversely along the support member. Each forklift member includes a respective mounting device slideably cooperating with the track assembly to mount each forklift member at the one of a plurality of positions transversely therealong. Each mounting device further includes a lock device releasably locking the respective forklift member to the track assembly at the one of a plurality of positions.